SMTP relay changelog

Emailit compares the addresses in Reply-To and From, ignoring display names and letter case. When they’re the same, it removes Reply-To before signing the message. Replies still reach the From address.

When the addresses differ, Reply-To is kept unchanged. See Email headers.

• The API and SMTP match the From domain without regard to letter case, so ada@Acme.com sends from the verified domain acme.com.
• Changing a domain’s tracking or inbound subdomain in the dashboard, or with tracking_key and inbound_key in Update a domain, now saves the new value. Publish the DNS record for the new name and verify it.

Open Email API → Logs to see successful and failed requests from the last hour up to the last 30 days. Filter by source (API or SMTP), outcome, method, path, status code, duration or API key, and open a request to see its request and response bodies. Sensitive values are redacted and long bodies are shortened.

See Request logs.

The sandbox rule now applies to the API, SMTP, Compose, retries, automations and campaigns. Sending to anyone else returns 403 with the code unverified_workspace_recipient from the API and 550 from SMTP, and campaign sends are blocked. Workspaces with production access aren’t affected.

To lift the restriction, verify a domain and request production access.

The reply lists the Emailit email ID of each recipient’s email, separated by commas when they fit on the reply line:

250 2.0.0 OK: queued as em_4yM2nTvR8oPcX3uZiKeLg7sB

Use the ID with Retrieve an email or to match email.* webhook events. See SMTP reply codes.

Requests over the limit are rejected instead of queued, so configure your client to send at most 2 emails per second or to retry rejected sends. The change was rolled out to workspaces gradually.

See Rate limits.